Conventionally, in optical communications using an optical transmission member such as an optical fiber and an optical waveguide, an optical module including a light emitting element such as a surface-emitting laser (for example, a vertical cavity surface emitting laser (VCSEL)) has been used. The optical module includes one or more photoelectric conversion elements (light-emitting element or light-receiving element), and a light coupling element for transmission or reception (hereinafter referred to as “optical receptacle”). An optical receptacle in which a structure for holding an optical transmission member is formed is known (see, for example, PTL 1).
FIG. 1 is a sectional view illustrating a configuration of optical module 10 disclosed in PTL 1. Optical module 10 disclosed in PTL 1 includes substrate 20, photoelectric conversion element 30 installed on substrate 20, and optical receptacle 40 formed of a transparent material. Optical receptacle 40 includes first optical surface 41; reflection surface 42; second optical surface 43; first recess 44 and second recess 45 that open at the top surface of optical receptacle 40; first insertion hole 46 configured for insertion of optical transmission member 50 from second recess 45 side and having both ends respectively open to first recess 44 and second recess 45; and second insertion hole 47 communicating between second recess 45 and outside and configured for insertion of optical transmission member 50 from the outside. In the following, the opening of first insertion hole 46 opening at the inner side surface of first recess 44 is also referred to as “first opening 461,” and the opening of first insertion hole 46 opening at the inner side surface of second recess 45 is also referred to as “second opening 462.”
First optical surface 41 allows incidence of light emitted from photoelectric conversion element 30. Reflection surface 42 reflects, toward second optical surface 43, light incident on first optical surface 41. Second optical surface 43 emits, toward the end surface of optical transmission member 50, light passing through the inside of optical receptacle 40 after entering optical receptacle 40 from first optical surface 41. In optical module 10 disclosed in PTL 1, optical transmission member 50 is inserted from the outside through second insertion hole 47, second recess 45 and first insertion hole 46 in this order, and is thus connected to optical receptacle 40. At this time, first insertion hole 46 functions as the guide of optical transmission member 50, and optical transmission member 50 is connected to optical receptacle 40 such that end surface 51 of optical transmission member 50 makes contact with second optical surface 43. In this manner, light emitted from photoelectric conversion element 30 is optically coupled to end surface 51 of optical transmission member 50 through first optical surface 41, reflection surface 42 and second optical surface 43.